Listening-in signal for telephone apparatus



G. I. GALITZKA.

LISTENING-IN SIGNAL FOR TELEPHONE APPARATUS.

APPLICATION FILED FEB. 20. L91?.

Patented Nov. 30, 1920.

Arromvfw.

UNITED 4Srs/frikis GEORGE 1. GALITZKA, or NEW YORK, N. Y.

LIS'.IEIBTG-INy SIGNAL FOR TELEPHONE APPARATUS.`

Leccese;

Specification of Letters Patent.' Patented N0V 30, 1920 Application vfiled February 20, 1917. Serial No. 149,718.

.To ald ytlf/tom t 72mg/ concem Be it known that I, Gnoncn I. GALirznA,

a citizen of the United States, and aresident of New York, borough of Manhattan,

. in the county of New`York and State of New Iork, have made and invented certain new and useful Improvements in Listening in Signals for Telephone Apparatus, of which the followingis ya speciication.V

ifiy invention relates to the art of telephony, and particularly to an apparatus for producing a warning signal in the subscribers line that the local switchboard-opera tors circuit is connected to the subscribers line and that the .operator is listeningdn.

A most frequent cause of complaint from apartment houses and other places where a local switchboard is maintained, is the` listening-in of the operator and .her subsefquent repeating .,thatiwhich. she has heard. It is accordingly an object of my invention to provide an apparatus which f will prevent the local switchboard operator from listening-in, the desired endy being attained without in any wise interfering with the local operator receiving instructions or conversing with the subscribers, as desired. In accomplishing the foregoing, I have provided an apparatus which will sound a warning signal in the subscribers receiver and in the receiver of the local switchboard operator immediately upon connecting in the subscribers line the local operators circuit. The warning si nal may be in the nature of a faint, but au ible, buzzing noise, and is only 'suliicient to remind the subscribers that their conversation is being listened to, and to notify the local operator of the fact that the subscribers are aware of her listening-in. The local switchboard operator, realizing that awarning signal will be sounded when her circuit is connected in the subscribers line, the moral effeet will thus prevent the operator from listening-in- Vith the above and other objects in View,

and with the aim toattain the aforemen-- tioned ends in a simple and expeditious manner, and with a view of not in any wise interfering with the various circuits and operations of the telephone, my invention res sides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment; of the inventionimay madel within the scope of what is claimed without departing from the spirit'thereof;

The ypreferred embodiment of my invention is disclosed in the accompanying drawings, wherein: Y i

`Figurel is a View in perspective of a telephone'switchboard such asis used in apartment houses, hotels, etc., where considerable trouble has been experienced, due to the listening-in ofthe local switchboard operator;

Fig l2 is a diagrammatic view of the electric circuits whereby a warning signal is mechanically produced in .the subscribers circuit that 4the localV operator is 1istening-1n; y y

F ig. 3 is adiagrammatic View similar to the foregoing, whereinthe warning signal iselectrically produced' in a subscribers ciri cuit.

Referring specilically to the several views, and particularly to Fig. 2, the local operators circuit 10 includes a plurality of the usual type of keys 11, which are arranged for connecting the local operators circuit 10, with 'its transmitter 12 and receiver 13, into the subscribers line.

In order that a warning signal will be produced in the subscribers line A when thel key 11 is depressed and the operators circuit thus connected in the subscribers line circuit and the local switchboard operator listeningin, the moving element 15, of the operators listeningsinswitch and key 11, is provided with an insulated metallic projection 16. Spaced contact'points 17 are arranged beneath, and adapted to be bridged by, the projection 16 when the listening-in key 11 is depressed. An electric circuit 20 is connected to the contact points 17, (which latter accordingly act as a switch) and includes a source of electrical energy 18 and an electric buzzer 19. `The electric buzzer 19 is contained within the switchboard 21, and the noise produced thereby when the operators listeningin key is depressed is' sufficient to impress a warning signal upon the operators transmitter 12 and so notify the subscribers that their conversation is being listened to. The warning signal maybe accentuated and magnified by placing a supplemental transmitter 22 directly in front ofthe electric buzzer,

should it be so desired.r` Y

Other ways of mechanically produclng a warning signal in the local operators transmitter when the listening-in key is depressed will readily suggest themselves to those skilled in the art, and I therefore do not limit myself to the exact arrangement as above described.

As illustrating a manner in which the warning signal may be electrically impressed upon the subscribers line circuit, reference is had to Fig. 8 of the drawings, wherein I have provided an electric` circuit 23 which includes a circuit breaker 24, capable of intermittently making and breaking the circuit, and a source of electrical energy 25. The electric circuit 23 is directly connected to thelocal operators transmitter circuit 26. The operators listening-in keys 1l are provided with the insulated projections 16', which are adapted to complete the circuit 23 across the spaced points 17. Vith this arrangement, should the operator fail to return the listening-in key to its upright position after the subscriber has obtained the desired party, the prolonged action of the circuit breaker 24;, by impressing either an intermittent or variable electromotive force upon the local operators circuit, will accordingly warn and notify, the subscribers that their `i conversation'is being listened to. The local operator, however, realizing that the subscribers are aware of her listening-in, will be prevented from so doing.

ln a telephone apparatus of the class described, the combination with a local operators switchboard of a local operators circuit including a transmitter and receiver, listening-in key switches adapted to connect the local operators circuit to a subscribers line circuit, supplemental circuit closing members carried by said listening-in key switches, contact points operating in conjunction with said supplemental *circuit closing members which are carried by the listening-in key switches, and a circuit connected to said contact points and including means `adapted to continually produce an audible warning signal in the subscriber-s receiver when any of the listening-in key switches is in closed postion and the local operators circuit, including the transmitter and receiver, connected. to the line.r

Signed at New York, borough of Manhattan, in the county of New York and State ot New York, this 19th day of February, A. D.

j GEORGE I. GALITZKA.

Witnesses Y .ANNA V. VALSH, e ETHEL H. ARCHER. 

